A super junction is a region of alternating conductivity types in a substrate. Super junctions are used to reduce a resistance of a transistor during an “on” state. Super junctions also help to increase breakdown voltage in comparison with transistors which do not include super junctions.
In some approaches, the super junction is formed using a straight walled trench opening in a doped substrate. The straight walled trench has sidewalls which extend perpendicular to a top surface of the substrate. The trench opening is then filled by one or more epitaxial depositions in order to form the alternating conductivity type regions. In some approaches, the trench openings are subjected to a tilted ion implantation process to introduce a dopant species opposite to that of the doped substrate.